A more quiet ride!

There have been several threads about this very subject. Do a search you will find them. As far as adding sound deadening, yes I could use a little more, but its not enough to get all worked up over!!! However to each his/her own!!

 

The larger, 1.8L engine won't have to spin up as fast as the current 1.5L. It also has EGR at high power settings to keep the exhaust gas from burning out the catalytic converter and that should reduce the sound. Also, you'll notice the photos show a nearly completely sealed underbody that blocks noise reflection from the road and further isolates the exhaust pipe. Aerodynamic improvements should reduce noise generating turbulence. Finally, the tires are a little larger and though I don't have any studies to support it, their reduced drag and improved foot-print should reduce tire noise.

Today's Prius is in the 10% of quietest cars as measured in Europe but the new one should be significantly quieter.

Bob Wilson

 

H'mmmm

Thank You Well said!!

You may pose that question again on the 26th!

I was speaking of my own 08 Barcelona Red Baby!! She can be a wee bit noisy on a rough road. On Blacktop its fine! I am debating on whether to up the anty with extra floor board insulation, it would be a bit of work! May start by just doing the tire well and rear end and see how it goes from there.

 

I think that bringing a decibel meter to the first Prius drive test is an excellent idea. Radio Shack sells a couple of cheapos, in case nobody has one handy.

 

I don't find our Prius particularly quiet at all. Its not loud...but its not quiet.

 

Hi Fred,

The Prius is so quiet, as is (except for full throttle accellleration, or up steep hills), that the sound deadening is really just for isolating the noise of other vehicles, and the occaisional pot hole. On smooth pavement, with no other cars around, cruising, its very quiet.

The people who have added sound deading have done it primarily to avoid secondary excitation of the car doors and floors in response to high powered audio systems.

 

Thanks to one of the other members, I was able to download the May 2008 European ratings for all vehicles. This includes the sound level as well as:

Manufacturer Model Description Transmission Engine Capacity Fuel Type Metric Urban (Cold) Metric Extra-Urban Metric Combined Imperial Urban (Cold) Imperial Extra-Urban Imperial Combined CO2 g/km Fuel Cost 12000 Miles Noise Level dB(A) Emissions CO Emissions HC Emissions NOx Emissions HC+NOx Emissions Particulates
​

The Prius is in the top 151 of 3293 vehicles at 69 dB. The measured sound levels for all vehicles ranged from 66.0 to 77.0 dB. As others have pointed out, we hear the engine at higher power settings. But there is one other noise source, tire noise on some cement highways.

When I attended HybridFest last year, I noticed that many of the Wisconsin and Illinois highways caused unusually loud, tire noise, compared to the roads I ride further South. Sound deadening under the floor would help.

Part of the problem with the NHW11 that led to some sound deadening efforts may have been the engine noise contrast. Up until about 3,000 rpm, my car quietly coasts. But above 3,000 rpm, the sound level is more noticable.

Bob Wilson

 

Road noise is the biggest offender for me. My Prius is better with Micheline tires, but still you get a lot of tire noise on some roads. Some of our highways have micro groves, and they make the tires hum and howl. On a smooth road my 2006 Prius is unbelievably quiet.

Tom

 

another problem is that with absence of engine noise, other noises are amplified.

i applied 3M noise absorbtion tape to my prius doors for lower noise, and indeed road/tire noise was lower which amplified engine noise and actually made it worse for me, IMHO

 

The Prius is quiet when its on stealth, but the engine is very harsh sounding and feeling, and the CVT causes that engine to drone under any type of acceleration load.

The car also lets in a lot of road noise. For instance on the Prius and the Lexus I am running the same tires, the Prius has far, far more road noise.

I looked at the chart, those dBA levels seem high to me across all cars...for instance they have the Lexus GS as quieter than the LS, which for anyone who has ever driven the two knows is not the case...

They also have the BMW 1 series quieter than the 7 series...

 

they are testing in lab conditions... so objective results.

what companies do right now is have "bad" and "good" noises.. good ones are supposed to drain out bad ones.

Because hybrids have much lower droning noises than normal cars, toyota introduced new system on japanese crown hybrid that uses speakers to input droning noise that cancels out "bad" noises.

I am pretty sure new prius will be quieter than old one.

 

Hi Bob Wilson,

You probably did not get a chance to look closely, like 3 inches from, those cement highways in Illinois. They are grooved laterly every inch with a half inch wide groove. Believe me, they are loud in any car.